A navigation apparatus is known as navigating a user to a destination or displaying a map as needed. Generally, the above navigation apparatus reads map information from a recording medium such as a CD-ROM based on a speed, heading direction, present position or the like of a user or a vehicle to thereby display a peripheral map including the present position in a liquid crystal display monitor etc. The navigation apparatus further calculates a guidance route from a predetermined departure point to a predetermined destination point and displays the present position and the guidance route.
Further, a navigation apparatus disclosed in Nonpatent Document 1 has a function to display marks such as triangles in regular intervals on the guidance route near a predetermined guidance point or navigating point such as a destination point or an intersection where a left/right turn is needed. In such a function, the display of the map is enlarged greater as the present position is closer to the guidance point.
Further, the displayed distance of an interval (namely, the displayed visible interval between the marks) for indicating a guidance route is generally fixed regardless of the change in scales of maps. Therefore, even if the scale of the map is changed, the displayed distance of the interval between the marks is not changed. Thus, in the navigation apparatus in Nonpatent Document 1, when the map scale is changed, a user has a difficulty in intuitively recognizing a real distance of the interval on the map.                Nonpatent Document 1: “Volvo XC90 ROAD AND TRAFFIC INFORMATION” Volvo Car Corporation, EU, p 11        